1. Field of the Invention
The present invention relates generally to the field of gas supply for a point of use. More particularity, the present invention concerns the generation and supply of gas of high humidity.
2. Description of the Related Art
Highly humidified, or near saturation, flow gases of variety are often required at a point of use such as a reaction chamber of a semiconductor wafer processing equipment. Some example gases are air, Nitrogen, Oxygen or an inert gas such as Argon. Typically, the required relative humidity is 90% and above. Such a high relative humidity of the flow gas, being near the point of condensation, is difficult to reach and maintain near a constant state. Many current humidification methods require large humidity contact surfaces and/or humidity contact time to reach near saturation. Some current example methods are:                1) Bubbling the flow gas through a liquid medium to gain humidity. The liquid medium can be water or a water containing solution.        2) Pressure techniques through a small orifice to spray and atomize the water into the flow gas.        3) Membranes with capillaries under pressure for separation of water into a mist for humidification of the flow gas.Therefore, a compact, effective and fast acting method for near saturation humidification and control of a gas flow is desired.        